San Mateo’s Halloween forecast calls for cool, mostly cloudy conditions Saturday, Oct. 31, with a slight chance of rain Saturday night.
The National Weather Service forecast, updated at 11:46 a.m. Wednesday, Oct. 28, predicts a Saturday high near 64 degrees. It does not specify when Saturday night’s slight rain chance begins.
Saturday night’s low is forecast to be around 50 degrees. That is the overnight minimum, rather than a prediction specifically for trick-or-treating hours.
Halloween weekend forecast
The forecast calls for mostly cloudy skies Thursday, Oct. 29, with a high near 69 degrees.
Friday, Oct. 30, is expected to be sunny, with a high near 67. Saturday brings mostly cloudy skies, followed by partly cloudy conditions and a slight rain chance overnight.
Sunday, Nov. 1, is forecast to be sunny, with a high near 67.
Bay shoreline flooding risk
A separate NWS coastal flood advisory covers Bay shoreline locations, including the San Francisco Bay shoreline, through 6 p.m. PDT Saturday, Oct. 31.
High tides can flood low-lying shoreline areas and cause isolated road closures. This flooding risk can occur even without rainfall.
The weather service advises travelers to allow extra time where roads are affected and avoid driving around barricades or through water of unknown depth.
Residents should check the latest forecast as Halloween approaches.
